1.High-quality materials: The automatic door closer is made of high-quality zinc alloy and stainless steel, spring-loaded, fully automatic closing, one-piece design and electroplating process make the spring door closer rust-proof, corrosion-resistant, sturdy and durable, and has a long service life. 2.Quiet and safe: The adjustable hidden door closer uses nylon rollers to open the door smoothly without scratching the door surface.It can reduce the noise when closing the door, reduce the damage to the door caused by violent impact, and avoid forgetting to close the door. 3.Adjustable design: Our indoor automatic door closer features an adjustable design.You can use the included adjustment lever to insert it into the pivot hole and adjust the closing force according to your needs, and the adjustable screw is used for slow or fast closing to increase the convenience of closing the door. 4.Easy to install: This spring door closer is easy to install and can be installed on both left and right doors.Threaded connection, easy assembly and disassembly, durable and smooth use, improving efficiency and practicality. 5.Scope of application: The door closer spring is suitable for doors weighing 20 kg.Suitable for metal doors, security doors, fire doors, wooden doors, etc.;it is an ideal choice for home, office and hotel room doors.